Boiler-alarm.



PATENTED AUG. 2, 1904.

A. ALTMANN.

BOILER ALARM.

APPLIGATION FILED MAR. 2. 1903.

NO MODEL.

UNITED STATES Patented August 2, 1904.

PATENT QEEICE.

BOlLER-ALARNI.

SPECIFICATION forming part of Letters Patent No. 766,576, dated. August 2, 1904.

Application filed March 2, 1903. Serial No. 145,768. (No model.)

To (1,71 wiz/7111, 7'15 71mg/ concern: Be it known that l', ADoLrH IXLTMANN, a

subject of the Emperor of Germany, residing.

at Berlin, in the Empire of Germany, have invented a new and useful Boiler-Alarm Apparatus, of which the following is a specification.

My invention relates to a boiler-alarm apparatus which is especially suitable for steamgenerators composed of a plurality of narrow tubes and having but a small content for water to be evaporated, so that the generators are liable to be emptied in a very short time if not attended to properly, when their plates, tubes, and so on will burn through and an explosion may occur. The new boiler-alarm apparatus is destined more particularly for similar steam-generators of automobiles and other autovehicles where it is of the highest importance-to protect the boiler from damage and explosion in case the driver should have neglected or forgotten to attend at the proper time to the feeding device previously disengaged or withdrawn or in case the water-gage should be choked and therefore misleading.

The object of my invention is to provide a boiler-alarm apparatus that can be conveniently attached to the steam-generator of an automobile and other autovehicle and safely handled, even where the space is very limited. This apparatus is so arranged that a fusible plug is caused to fuse in case the water-level should sink below the allowed limit and a signal-pipe is sounded, while the driver alarmed is enabled to stop the further escape of steam and to avoid the danger for the boiler.

.In the accompanying' drawings, Figure l is a vertical longitudinal section through my boileralarm apparatus and a part of the boiler-wall, the signal-pipe being shown in elevation. Fig. 2 is a horizontal section through the line l1/ in Fig. l; and Fig. 3 shows, partly in elevation and partly in section, a modification of the boiler-alarm apparatus, parts being broken away.

Similar letters of reference refer to similar parts.

The alarm apparatus essentially consists of a casing u, a stop-valve I), a removable hollow and perforated fusible-plug' holder c, and a signal-pipe g. The casing fzy has the shape of a T-pieee and is attached to a wall A of the steam-generator by means of its screw-threaded branch e, which is screwed into a suitable socket q of the wall or its equivalent. The casing a has two partition-walls, whereby its cavity is divided into three chambers t, f, and f. The chamber t is permanently in open communication with the water-space of the boiler by means of the channel a' and can be put into open communication with the adjoining chamber u' by means of the aperture in the one partition-wall on opening the stopvalve with the aid of the hand-wheel b2 and the screw-spindle tightened by a stuiingbox y'. The upper end of the casing a is provided with an internal screw-thread,into which the screw-threaded part ym of the fusible-plug holder c is screwed, while its shoulder bears against the second partition-wall or preferably against a packing-ring Y, inserted bctween them. Thus an annular chamber f is formed between the internal wall of the casing el` and the groove in the threaded part m. This chamber f freely communicates both with the cavity of the holder c through several (here four) holes n and with the signal -pipe g through a channel f. The signal-pipe g may be of any known construction and attached to the casing a by means of a nut s, fitted tothe threaded projection containing the channel f. T he holder c projects into the chamber /z' down to near the aperture 1 and is provided on its end with a conical hole J, in which the conical fusible plug' d is placed and secured by means of a cap L, screwed on the externallythrcaded end projection of the holder c. This cap /L is provided with a hole /Ll to allow steam to act upon the fusible plug (Z. The cavity of the holder c can be closed by a tap 2). The upper end o of the holder c is hexagonal, so that the holder c can be turned by a spanner for screwin0` it into the casino' a and aeain unb D b screwing it.

The alarm apparatus is connected with the steamgenerator in that lowest water-level which is still a little above the highest points of the heating-surfaces, so that the latter are covered with water, and an immediate danger of the boiler-plates burning' through and an IOO explosion arising therefrom is avoided. In the drawings the average water-level is assumed to prevail in the generator, so that on opening the stop-valve also the middle chamber z' of the casing a is mostly filled with water, above which air is contained in this chamber and compressed up to a pressure equal to that in the generator. The water contained in the casing a has, however, a temperature that is a little lower than in the boiler, owing to the loss of heat through radiation.

Vhen the water-level in the generator is assumed to sink by omitting' to put the feedingpump into operation at the proper time until this level reaches the channel then steam will pass through the channel e', the chamber t, and the aperture and enter the chamber /zl and allow the water therein to flow off into the generator. The heat of the steam will act upon the fusible plug, so that the latter being made of the proper composition will fuse and allow the steam to pass through the cavity of the holder c, the holes n, the chamber f, and the channel f to the signal-pipe g, which will then sound and call the driver. By closing the stop-valve b the driver can stop the further escape of steam, after which he again raises the water-level in the boiler by putting the feeding device into operation..

The fusible plug, now destroyed, requires to be replaced by a fresh plug after the holder c has been taken out of the casing a and the cap It has been removed. This operation is very easy, as only a spanner need be applied and the hexagonal end 0 of the casing is perfectly free. The signal-pipe g is preferably bent downward, as shown, to adapt the apparatus to restricted spaces.

Vhere the spaces are not limited or where circumstances allow it, however, the signalpipe may be placed upright on the upper end of the holder c. This is illustrated by Fig. 3, in which the erect signal-pipe g is screwed into the hexagonal end o of the holderc and communicates freely with the cavity of the latter. In this case of course no groove and no holes n are required in the threaded part m.

The boiler-alarm apparatus described so far may be varied in its details without deviating from the spirit of my invention. vThe stop-valve may be replacedv by its equivalents, such as a cock, since the only purpose of this stop-valve or the like is to stop the further escape of steam after the signal-pipe has sounded and called the driver.

W'hat I claim as my invention, and desire to secure by Letters Patent, is-

The combination with a steam-generator, of a casing having at the upper end an internal screw-thread and a hole, a channel for connecting the lower end of said casing with said steamgenerator at the lowest water-level, means for opening and closing said channel, a tube-like holder projecting into said casing through said hole and provided with a hexagonal upper end, an external screw-thread therebelow and fitting into said internal screwthread of said casing, a plurality of lateral holes in this screw-thread and a conical mouth in the lower end, a removable fusible plug placed in said conical mouth of said tube-like holder, an annular cap for securing said fusi- ADOLPH ALTMANN.

Witnesses HENRY HAsrER, VVOLDEMAR HAUPT. 

